Field of the Invention
The present invention relates to a method and system for WiBro (Wireless Broadband) network interworking in a wireless terminal.
Description of the Related Art
WiBro is a wireless broadband Internet technology being developed by the Korean telecoms industry. WiBro is the Korean service name for IEEE 802.16e (mobile WiMAX) international standard.
Advanced wireless data communication technology widens the width of selection for users of wireless data service by building a wireless network using different types of wireless techniques (e.g., WLAN 802.11a/b/g, 3G HSDPA, WiMAX, WiBro, etc.).
In particular, a WLAN (Wireless Local Area Network) environment using an unlicensed band is widely used because of its relative advantages, such as low connection cost, even though it does not provide mobility.
A UMTS-WLAN (Universal Mobile Telecommunications System/Wireless Local Area Network) interworking wireless router for providing connectivity to WiFi users is already available in a 3G network. Normally, a wireless (mobile) router serving unlicensed band users in an IPv4 environment uses Network Address Translation (NAT).
A NAT technique was developed for allowing several users to access a network by sharing one or more public IP addresses taking into account insufficiency of IP addresses. Several WiFi users are assigned one private IP address and have access to the Internet by sharing one public IP given to the router.
Translation of TCP/UDP port information should be performed so that one public IP is shared by several users. The translation is called “IP masquerading” in a Linux environment.
The NAT was developed to address insufficiency of IPv4 addresses by allowing several WiFi users allocated respective private addresses to access a public IP network (e.g., the Internet) by using one public IP.
Accordingly, when users with their private addresses access the public IP network, visibility of the users by the public network is not considered to be an important issue. Public network providers do not use the NAT much because of unsatisfactory user management of the NAT.
The users are indistinguishable from each other following translation into the public IP (Internet Protocol) address. Since TCP/UDP (Transmission Control Protocol/User Datagram Protocol) ports are also translated for each user service, users are not distinguishable by use of the ports.
Of course, a NAT-based router is able to manage traffic and QoS (Quality of Service) for each user by using a private address through packet-specific processing, but such management greatly affects performance of the network. Upgrading hardware as a solution to performance degradation increases a relevant cost.
Also, implementation of access disabling and enabling functionality for each user greatly increases complexity.